ABSTRACT: CASE REPORT: In a 57-year-old female owner of a dry-cleaning
shop, we describe the association of severe bilateral optic neuritis with
unexpectedly high concentrations of perchloroethylene/metabolites in the
blood and of chloroform in urine. Visual disturbances consisted of complete
blindness for 9 days in the left eye, for 11 days in the right eye, with
bright phosphenes and pain on eye rotation. Only central (2-3 degrees radius)
vision recovered in the following months. CONCLUSION: Although environmental
concentrations of perchloroethylene were within normal limits, we measured
five-fold increases in vapors emitted when ironing freshly dry-cleaned
fabrics, and suggest that inhalation of perchloroethylene vapors was the
cause of this case of ocular nerve toxicity, recapitulating a previous
report of major perchloroethylene toxicity.

TITLE: Perchloroethylene-induced nephrotoxicity in dry-cleaning workers:
is there a role for free radicals?

ABSTRACT: OBJECTIVES: To investigate whether employment in dry cleaning,
and potential exposure to perchloroethylene (PCE), were associated with
increased risk of carcinoma of the oral cavity and pharynx, larynx, oesophagus,
and gastric cardia. METHODS: Two population based case- control studies
were carried out. There were 491 cases of carcinoma of the oral cavity
and pharynx, 235 of the larynx, and 404 of the oesophagus and gastric cardia.
724 controls were selected by random digit dialing. Personal interviews
ascertained information on lifetime job histories, cigarette use, alcohol
consumption, and other potential risk factors. The probability and level
of exposure to PCE were estimated from the scientific literature. RESULTS:
People who worked in dry cleaning tended to consume less alcohol and cigarettes
than the general population. The adjusted odds ratio (OR) associated with
ever having worked in dry cleaning was 1.6 (95% confidence interval (95%
CI) = 0.6 to 4.4) for all cancer types together. The strongest associations
were with laryngeal (OR 2.7; 95% CI 0.6 to 10.9) and oesophageal squamous
cell carcinomas (OR 3.6; 95% CI 0.5 to 27.0). For laryngeal cancer, the
relative risk increased with number of years employed in the dry cleaning
industry (P = 0.14. The two cases of oesophageal squamous cell carcinomas
had worked in dry cleaning for only a short time. Analyses of subsites
showed higher risks for supraglottic laryngeal cancer (OR 5.7; 95% CI 1.0
to 32.1) and cancer of the tongue (OR 2.3; 95% CI 0.4 to 12.6). Analyses
of exposure to PCE yielded similar results. CONCLUSIONS: These findings
could easily be explained by chance; nevertheless, they are consistent
with previous reports of excess risk of oesophageal, laryngeal, and tongue
cancer, and suggest that previous studies of dry cleaners that could not
control for alcohol and cigarette use may have underestimated the relative
risks of such cancers.

ABSTRACT: A panel of immunological parameters has been examined in a
group of dry- cleaning workers (n = 21) and in a control group of administrators
(n = 16) from the same plant. The results were also compared to long-term
laboratory reference values (LRV) (n = 14-311). External exposure to tetrachloroethylene
(PER) was represented by TWA (8 h) values in the range 11-752 mg PER/m3.
Biological monitoring showed an amount from 9 to 344 mg PER/m3 in exhaled
air by the end of workshift. 1. The exposed dry-cleaning workers compared
to the controls from the plant had statistically significant changes in
metabolic activity of phagocytes, alpha 2-macroglobulin, C3 and C4 complement
component, salivary secretory IgA, and blastic transformation test. Most
of the values were within the range of normal values. 2. The exposed dry-cleaning
workers had several abnormal immune parameters compared to the long-term
laboratory values (LRV) especially in the alpha 2-macroglobulin, C3 and
percentage of T-lymphocytes. Most of the changes, even those that were
statistically significant, were still within the range of normal values,
but they might be classified as trends or shifts away from normal (spontaneous
blastic transformation, absolute number of phagocyting cells, coeruloplasmin,
circulating immunocomplexes, serum lysozyme). 3. The non-exposed controls
from the same plant showed both quantitative and qualitative differences
when compared to the LRV. Changes were seen in IgG, C4, CSI and in increased
spontaneous metabolic activity of leucocytes, total leucocyte count, absolute
number of phagocyting cells, alpha 2-macroglobulin, prealbumin, C4, circulating
immunocomplexes and serum lysozyme. 4. The distribution analysis of all
results detected a large number of abnormal values in both groups, more
in the at-risk group. 5. As inhalation was the main route of PER exposure
it was concluded that the changes might represent aspects of the response
of the respiratory immune system, mainly of the alveolar macrophages. Additional
postinfection effects could not be excluded in both studied groups. Individual
differences in immune reactivity as well as individual range of exposure
should be taken into consideration.

ABSTRACT: Methods for monitoring personal exposure to tetrachloroethylene
vapour in the dry cleaning industry have been investigated. A Draeger diffusive
colorimetric gas detector tube and the Delta vapour detection system manufactured
by Sabre Gas Detection were both shown to be suitable for preliminary on-site
monitoring. A range of short-term pumped colorimetric tubes were also shown
to perform well under a range of environmental conditions. Data on laboratory
evaluations and field trials are presented.

TITLE: Coin-operated dry cleaning machines may be responsible for acute
tetrachloroethylene poisoning: report of 26 cases including one death.

ABSTRACT: BACKGROUND: Incorrect operations by customers are not uncommon
in coin- operated dry cleaning establishments; dry cleaning machines may
also be poorly maintained. This may result in retention of large amounts
of the cleaning solvent in dry cleaned items. CASE REPORT: A 2-year-old
boy was found dead in his bed, with a strong odor of solvent in the room.
Toxicological analysis demonstrated tetrachloroethylene poisoning. The
solvent had been retained in the double curtains of the bedroom which had
been dry cleaned in a coin-operated establishment the same day. A retrospective
study at the Paris Poison Center revealed 25 additional cases, all with
a favorable outcome. Analysis of the circumstances of these accidents showed
that the main causes of tetrachloroethylene retention in clothes are overloading
of the machine and dry cleaning of bulky items. However, failure of the
dry cleaning machine may also be involved. CONCLUSIONS: To immediately
reduce the health risks, consumers were informed both via the mass media
and by warnings in coin- operated dry cleaning shops. A second batch of
preventive measures is in preparation including modifications of the machines
to limit solvent exposure and a specific regulation concerning their inspection
and maintenance.

ABSTRACT: OBJECTIVE--To determine if subclinical hepatotoxicity is associated
with exposure to perchloroethylene at concentrations commonly experienced
in the workplace, and whether surveillance with serum hepatic transaminase
activity underestimates such effects. METHODS-- Hepatic parenchymal echogenicity
on ultrasonography and serum hepatic transaminase activity were compared
in 29 community based dry cleaning operators exposed to perchloroethylene,
and a control group of 29 non- exposed laundry workers. Perchloroethylene
exposure was assessed by work history and air monitoring. RESULTS--Mean
hepatic transaminase activities were minimally increased in dry cleaners
compared with laundry workers. Increased alanine aminotransferase activities,
between 1.0 and 1.5 times the normal limits, were found in five of 27 (19%)
dry cleaners compared with one of 26 (4%) laundry workers. In contrast,
diffuse parenchymal changes in echogenicity, as determined by hepatic ultrasonography,
were increased nearly twofold in dry cleaners, occurring in 18 of 27 (67%)
dry cleaners compared with 10 of 26 (39%) laundry workers (P < 0.05),
and were most strongly associated with increased perchloroethylene exposure
in older dry to dry or wet transfer operations (odds ratio 4.2, 95% confidence
interval 1.1-15.3). Mean eight hour time weighted average perchloroethylene
exposure for dry cleaners was 16 ppm, which is less than the permissible
exposure limit of 100 ppm in the United States. CONCLUSIONS--It was concluded
that mild to moderate hepatic parenchymal changes occur more frequently
in workers exposed to perchloroethylene than in populations not exposed
to chemical solvents, and that these effects are underestimated by serum
hepatic transaminase activity.

ABSTRACT: The effects of chronic low-level tetrachloroethene (TCE) exposure
on functions of the central nervous system (CNS) were measured in subjects
living in the neighborhood of dry cleaning shops with a mean residential
time of 10.6 years. Neurobehavioral tests were performed using a German
version of the NES battery. Additionally, a pattern reversal visual-evoked
potentials (VEPs) were recorded. The mean blood TCE concentration in the
subjects was 17.8 micrograms/liter and the median indoor TCE air concentration
measured in the residences was 1.36 mg/m3. The outcome of the NES subtests
for vigilance, simple reaction time, as well as visual memory differed
statistically significantly between the exposed subjects and the controls,
whereas for VEP latencies the differences were statistically not significant.
It is concluded that despite the low exposure levels, CNS functions might
be affected by TCE in subjects living close to a dry cleaning facility
if the exposure lasts for several years.

TITLE: Cancer in relation to occupational exposure to perchloroethylene.

ABSTRACT: Exposure to perchloroethylene (PCE) occurs in a number of
occupational settings in which organic solvents are used, and, in particular,
is widely prevalent in the dry-cleaning industry. This review summarizes
the results of studies of the occurrence of the individual types of cancer
in dry cleaners. Two of those cancers of greatest a priori concern (because
of results in PCE-exposed experimental animals)--liver cancer and leukemia--have
not occurred with increased frequency among persons employed in the dry-cleaning
industry. Rates were elevated by about a factor of two for esophageal and
bladder cancers, but not increased clearly for any other site. The excess
mortality from esophageal cancer was well beyond the limits of chance,
based on a total of 23 deaths that occurred in the two principal cohort-studies
of dry cleaners. There was some indication of a particularly high risk
associated with prolonged employment and a long interval since first employment.
However, the possible confounding effect of the combination of cigarette
smoking and heavy alcohol consumption, a very strong risk factor for the
development of esophageal cancer, could be taken into account only partially
in these studies. With regard to bladder cancer, the limited data available
suggest that the observed increased risk could be due to exposure to other
solvents than PCE used in dry cleaning. The potential influence of occupational
exposure to PCE on the occurrence of esophageal and bladder cancer needs
continued examination in further follow-up of existing cohorts of dry cleaners,
the assembly of additional cohorts, and in large case-control studies that
ascertain occupational exposures in some detail.

ABSTRACT: Perchloroethylene exposure in 28 dry-cleaning establishments
and in 25 homes occupied by dry cleaners in Modena, Italy, was investigated.
Environmental air samples and alveolar air samples from dry cleaners (n
= 60) and from their family members (n = 23) were collected. The degree
of perchloroethylene on the dry-cleaning premises varied widely from establishment
to establishment. Spot sampling ranged from 0.6 to 75 mg/m3, whereas sampling
by personal passive dosimeters ranged from 2.6 to 221.5 mg/m3 (8-h time
weighted average values). Perchloroethylene in alveolar air samples collected
at the end of the work day correlated closely with the 8-h time weighted
average values (r = .750, p = .001), and correlated also with alveolar
air samples collected at home in the evening (r = .665, p = .001) and the
following morning (r = .549, p < .001). Perchloroethylene levels inside
the homes of dry cleaners appeared significantly higher than in 29 houses
selected as controls (Mann Whitney U test, p < .001). Perchloroethylene
in alveolar air samples collected at home suggests that nonoccupational
exposure to perchloroethylene for family members of dry cleaners exists.

ABSTRACT: Unlike the impressive advancement of cancer risk assessment,
the "cutoff approach" based on hazard quotient in noncancer risk assessments
recommended by the EPA has crucial deficiencies. Several alternative approaches
have been suggested in the literature to modify the noncancer risk characterization
based on reference doses. Recent studies have indicated that the effects
of perchloroethylene (PERC) on the central nervous system (CNS) is a much
more sensitive noncancer endpoint than cancer which is currently the basis
for deriving its public health criteria and standards. Studies indicate
that 20 ppm of inhaled PERC concentration elicited adverse effects on the
CNS in experimental animals and humans. However, the existing EPA oral
reference dose (RfD), a noncancer toxicity parameter for PERC (0.01 mg/kg/day),
is based on the induction of hepatotoxicity and increased body weight gain
induced by PERC in rats. An attempt was made in this paper to examine whether
logistic regression of dose-response data could be applied to assess the
noncancer risks. In order to perform logistic regression the inhalation
toxicity data of PERC were classified according to the severity of toxicity
paradigm used in toxicity analysis. Based on the sensitive noncancer endpoints
identified from severity classification, a logistic regression analysis
of the data was performed and its potential applicability in noncancer
risk characterization was described for workers exposure to PERC in dry-
cleaning operations.

TITLE: Concentrations of tetrachloroethene in blood and trichloroacetic
acid in urine in workers and neighbours of dry-cleaning shops.

ABSTRACT: Tetrachloroethene concentrations in blood and trichloroacetic
acid concentrations in urine were determined--primarily over the course
of a week--for 29 persons living in the vicinity of dry-cleaning shops.
The mean levels of tetrachloroethene increased during the week. In some
neighbours concentrations were exceeding the German biological threshold
limit value for tetrachloroethene (1000 micrograms/l blood), persisting
over the whole week in one case. The concentrations of tetrachloroethene
in blood depended on the floor and the construction type of the building
where these people were living, but not of the type of system used in the
dry-cleaning shops. 5 of 12 dry-cleaners were found to have tetrachloroethene
levels exceeding the German biological threshold limit value, some of them
by a considerable amount.

TITLE: Neurobehavioral and neuroendocrine effects of occupational exposure
to perchloroethylene.

AUTHOR AFFILIATION: Laboratory of Industrial Toxicology, University
of Parma, Italy.

SOURCE: Neurotoxicology 1992 Spring;13(1):243-7

CITATION IDS: PMID: 1508425 UI: 92375385

ABSTRACT: The hypothesis that long-term low-level exposure to perchloroethylene
(PERC) may impair the dopaminergic control of prolactin (PRL) secretion
and negatively affect neurobehavioral performance, was tested in a cross-sectional
survey of dry-cleaners. Sixty female workers exposed to PERC in dry-cleaning
shops and thirty controls recruited in a cleaning plant not using solvents
were examined. PERC air concentration during four-hour random periods varied
from 1 to 67 ppm (median 15 ppm). PERC blood levels ranged 12-864 mg/l
(median 145 mg/l). A set of tests from a computer-based performance evaluation
system was administered, including Finger Tapping with both dominant and
non-dominant hands, Simple Reaction Times, Digit Symbol, and Shape Comparison
in two different versions constructed to test Vigilance and the response
to moderate stress, respectively. During the proliferative phase of the
menstrual cycle, PERC-exposed workers showed increased serum PRL (12.1
+/- 6.7 ng/ml) as compared to their matched controls (7.4 +/- 3.1 ng/ml,
p less than 0.001). Prolonged reaction times were also observed in all
tests. However, neither the duration of exposure nor air and blood PERC
concentrations were significantly correlated with performance. Nor were
exposure variables associated with the increased PRL levels.

TITLE: A comparative study of human levels of trichloroethylene and
tetrachloroethylene after occupational exposure.

AUTHORS: Skender LJ; Karacic V; Prpic-Majic D

AUTHOR AFFILIATION: Institute for Medical Research and Occupational
Health, University of Zagreb, Yugoslavia.

SOURCE: Arch Environ Health 1991 May-Jun;46(3):174-8

CITATION IDS: PMID: 2039273 UI: 91247869

ABSTRACT: The rate of trichloroethylene (TRI) and perchloroethylene
(PER) absorption was investigated in workers who were (1) occupationally
exposed to TRI in four dry-cleaning shops (Group 1, n = 10) and (2) occupationally
exposed to PER in one dry-cleaning shop (Group 2, n = 18). Concentrations
of TRI and PER in blood were analyzed, and concentrations of trichloroethanol
(TCE) and trichloroacetic acid (TCA) in blood and urine were analyzed.
Results varied widely: PER was found in the blood of workers in group 1,
but TRI was not detected in blood from any worker in group 2; most blood
samples from group 2 workers did not contain a detectable quantity of TCE,
and urine TCE concentrations in this group were very low. During the work
week, a significant difference was found in group 1 for TRI in blood and
TCE in blood and urine. In group 2, however, the only significant difference
during the work week was for PER in blood. Therefore, the most reliable
biological indicators for TRI and PER exposure are TCE in blood and PER
in blood, respectively.

AUTHOR AFFILIATION: School of Public Health, University of Michigan,
Ann Arbor.

SOURCE: Am J Ind Med 1991;20(5):601-14

CITATION IDS: PMID: 1793103 UI: 92170813

ABSTRACT: Perchloroethylene (PCE) is a widely used dry cleaning and
degreasing solvent. Although there is evidence in animals and humans for
renal effects at extremely high doses, there are few studies of its potential
renal toxicity at typical occupational concentrations. This study reports
on the relationship of PCE in breath and estimates of chronic exposure
with the urinary ratios of total urinary protein, albumin, and n-acetyl-glucosaminidase
(NAG) to creatinine in dry cleaning workers exposed to PCE. Regression
models including one or more exposure variables, demographic variables,
mean arterial blood pressure (MAP), and the presence of diseases affecting
kidney function were examined. Urine samples, breath samples, exposure
histories, and medical histories were obtained from 192 dry cleaning workers.
The results failed to demonstrate any consistent relationship between exposure
and renal outcome variables. However, protein/creatinine and albumin/creatinine
were significantly, although weakly and positively, associated with MAP;
NAG/creatinine was weakly but significantly positively associated with
age; mean NAG/creatinine was also higher in non-whites. The reasons why
an association between exposure and renal outcome was not found are discussed.

ABSTRACT: Subjective symptoms, hematology, serum biochemistry and other
clinical signs were investigated in 56 dry-cleaning workers exposed to
tetrachloroethylene at 20 ppm (as a geometric mean of 8-hr time- weighted
average), and the results were compared with the findings in 69 non-exposed
controls from the same factories. There were exposure- related increases
in the prevalence of subjective symptoms during the work as well as in
the past 3 month period, whereas there was no significant changes in hematology.
Effects of the exposure on liver and kidney functions were also negative
as judged by emission enzyme activities, BUN and creatinine in the serum.

AUTHOR AFFILIATION: Occupational Health Program, School of Public Health,
University of Michigan, Ann Arbor 48109.

SOURCE: Am Ind Hyg Assoc J 1990 Oct;51(10):566-74

CITATION IDS: PMID: 2251984 UI: 91068664

ABSTRACT: Perchloroethylene (Perc), the most widely used solvent in
dry cleaning, is toxic to the liver, kidneys, and central nervous system
and may be a human carcinogen. In the Detroit area, as part of a project
investigating the health status of dry cleaning workers, an exposure assessment
was carried out in dry cleaning plants using perchloroethylene. Breath
samples were obtained from each participant, and time-weighted average
(TWA) breathing zone air samples were obtained using passive dosimeters
on a subset expected to experience a range of exposures. Perc in breath
and Perc in air were highly correlated (r2 = 0.75, p less than 0.0001).
On average, operators of dry cleaning equipment experienced significantly
more exposure than nonoperators. Also, employees working in shops that
use transfer equipment (requiring physical transfer of Perc-saturated clothing
from washers to dryers) showed significantly higher exposure than those
in shops utilizing dry-to-dry machinery (permitting washing and drying
in one machine in a single cycle). One or more air samples in every transfer
shop exceeded the recently revised Occupational Safety and Health Administration
(OSHA) permissible exposure limit (PEL) of 25 ppm, while no air samples
in dry-to-dry shops exceeded this limit. The results suggest concern for
exposures to operators in transfer shops and that compliance with the PEL
is achievable by engineering controls with presently existing technology.

ABSTRACT: One hundred and one employees of dry cleaning shops exposed
to tetrachloroethylene (time weighted average 205 mg/m3) and 84 employees
of departmental stores and hotels were compared from the results of a psychological
examination. Age, gender, the daily consumption of alcohol and the intellectual
level were taken into consideration analysing the effects of tetrachloroethylene.
Perceptual speed, digit reproduction as a memory test, the digit symbol
test as a substitution task and variables of a choice reaction test as
well as a cancellation test differed significantly between the controls
on one hand, and the groups of low and high exposure on the other. But,
the differences between the exposure groups were not significant. There
was no effect of alcohol on the exposure-related group differences. By
means of discriminant analyses the diagnostic effectiveness of the biochemical,
neurological and psychological methods were compared to classify the subjects
into exposure groups. The highest rate of correct classifications was performed
by the multidisciplinary combination of approaches.

TITLE: Toxicokinetics of chlorinated hydrocarbons.

AUTHORS: Marth E; Stunzner D; Kock M; Mose JR

AUTHOR AFFILIATION: Institute of Hygiene, University of Graz, Austria.

SOURCE: J Hyg Epidemiol Microbiol Immunol 1989;33(4 Suppl):514-20

CITATION IDS: PMID: 2634072 UI: 90229698

ABSTRACT: Substitution of ethylene with halogen atoms leads to a highly
effective compound with a strongly lipophilic character. The most important
solvent in the dry cleaning process is tetrachloroethylene (PER). Owing
to its physical-chemical properties, it has become a ubiquitous environmental
pollutant. The uptake of small amounts of PER through polluted drinking
water does not lead to liver damage as originally suspected. On the one
hand, PER is taken up by erythrocyte membranes, on the other, it interacts
with chylomicrons. Thereby two transportmechanisms are provided by for
PER. Consequently, various physiological functions of both transport systems
are disturbed. The erythrocytes increasingly disintegrate and are broken
down in the spleen. Of all organs, the spleen shows the highest concentration
of PER. Also, disturbances in the lipid metabolism occur because chylomicrons
are broken down at a slower rate. Thereby, serum triglyceride concentration
increases. These lipids are increasingly stored in the fatty tissue leading
to the high accumulation of PER. A toxicological evaluation of chlorinated
hydrocarbons should therefore take into account the changes in the blood
system and in the lipoprotein metabolism.

ABSTRACT: Several experiments are reported which concern the possible
role of long-term occupational exposure in the etiology of dementia. A
case study of a male with memory impairment thought to be due to Alzheimer's
disease is reported. Neuropsychological testing revealed impairments in
short-term memory, which gradually cleared over months. Analyses uncovered
extremely high serum levels of a solvent (perchlorethylene) this individual
had used for decades in a dry-cleaning business. A case- series is also
reported in which four individuals with similar patterns of neuropsychological
performance were noted to share occupational exposure to metal vapors.
The results of a preliminary case-control study are also reported in which
an increased incidence of long-term occupational exposure to metals and
solvents was noted in patients with Alzheimer's disease. These results
suggest that the role of long-term occupational exposure needs to be thoroughly
investigated in patients diagnosed with Alzheimer's disease and other neurological
disorders.

ABSTRACT: To evaluate the carcinogenic potential from occupational exposure
to perchloroethylene (PCE), a retrospective cohort mortality study of workers
employed in the dry cleaning industry was conducted among 1,690 workers
from four labor unions. The majority of the cohort had potential exposure
to petroleum solvents as well as to PCE while working in the dry cleaning
industry. Mortality from primary cancer of the liver was of particular
interest, due to the findings of excess liver cancer in mice exposed to
PCE. Other sites of cancer were also of interest. A total of 493 deaths
were observed, whereas 575.5 were expected based on US mortality rates.
Mortality from all cancers combined was greater than expected (142 observed
v 122.9 expected). No deaths due to liver cancer were observed. Urinary
tract cancer was the only specific site where there was a statistically
significant excess in observed deaths (12 observed v 4.7 expected). There
was some consistency in these findings across the four individual unions
and across race/sex groups. A subcohort of workers who were employed only
in dry cleaning shops that used PCE as their primary solvent was identified
from the union records. There was only one death from urinary tract cancer,
whereas 1.3 deaths were expected in this subcohort.

TITLE: Occupational exposure to perchloroethylene in the dry cleaning
industry.

AUTHORS: Materna BL

SOURCE: Am Ind Hyg Assoc J 1985 May;46(5):268-73

CITATION IDS: PMID: 4003279 UI: 85222190

ABSTRACT: Field surveys were conducted of 67 dry cleaning establishments
to assess working conditions and potential for exposure to perchloroethylene,
a solvent of choice in this industry. Evaluation of ventilation controls
showed that 28% of cleaning machines (transfer type) did not have functioning
local exhaust systems, and an additional 32% had inadequately maintained
systems providing less than the recommended face velocity at the door opening.
Personal sampling was performed in 20 firms to relate operator exposure
levels to the process used and degree of local exhaust ventilation. Utilization
of the dry-to- dry (closed system) process resulted in a lower mean TWA
exposure, 28.3 ppm, as compared to 86.6 ppm for transfer operations. Five-minute
peak samples taken during clothing transfer demonstrated significant exposure
levels ranging from 11.3 to 533.8 ppm. A lower mean peak exposure (25.3
ppm) was found for firms with local exhaust ventilation at the recommended
rate than for facilities with poorly or unventilated cleaning machines
(159.7 ppm). The study points out the manner in which available control
measures can be used optimally to reduce employee exposure. Increased involvement
of trade associations and local health authorities is also recommended
to promote the safe use of perchloroethylene in the dry cleaning industry.

ABSTRACT: The National Institute for Occupational Safety and Health
(NIOSH) conducted industrial hygiene surveys at 44 commercial dry cleaning
facilities in five states as part of an industry wide study to assess the
health effects of long-term, low-level exposure to perchloroethylene (PCE).
Time-weighted average (TWA) and peak exposures to PCE were determined by
collecting personal air samples using activated charcoal tubes and battery-operated
pumps. TWA exposures of the machine operators ranged from 4.0 to 149.0
ppm PCE. The geometric mean PCE exposure of the machine operators (22 ppm)
differed significantly from the mean exposures of the pressers (3.3 ppm),
seamstresses (3.0 ppm), and the concentrations in the front counter areas
of the facilities (3.1 ppm). Te geometric mean 5-minute peak PCE exposure
during textile transfer was 44 ppm while the mean 15-minute exposure was
33 ppm. No significant differences were found between exposures when either
the TWA or the peak data were grouped by geographic location (i.e., state),
or by the type of processing equipment used (i.e., "Combination" units
vs. separate washing and drying units). Recommendations for work practices,
ventilation, maintenance, plant layout and personal protective equipment
are presented to reduce PCE exposures to lowest achievable levels.

TITLE: Leads from the MMWR. Exposure to perchloroethylene in US dry-cleaning
workers.

SOURCE: JAMA 1983 Jun 17;249(23):3159-60

CITATION IDS: PMID: 6854837 UI: 83216491

MAIN MESH HEADINGS: Air Pollutants/*analysis, Air Pollutants, Occupational/*analysis,
Tetrachloroethylene/*analysis

ABSTRACT: Behavioral, renal, hepatic and pulmonary tests were applied
to 22 subjects exposed to tetrachloroethylene in 6 dry-cleaning shops.
The results were compared with those obtained in 33 subjects non- occupationally
exposed to organic solvents. The intensity of exposure was monitored by
personal environmental monitoring and by urine analysis for trichloroacetic
acid and expired air and venous blood analysis for tetrachloroethylene.
The time-weighted average exposure to tetrachloroethylene amounted to 21
ppm (range 9 to 38 ppm). The correlation between the concentration of tetrachloroethylene
in ambient air sampled with the charcoal tube method and with a passive
dosimeter indicates that the latter can correctly estimate the time-weighted
average exposure to the solvent. In view of the long biological half- life
of tetrachloroethylene, the internal dose may be better estimated by measuring
its concentration in blood 16 h after the end of exposure (i.e. before
resuming work the next morning). The present study suggests that if the
blood concentration of tetrachloroethylene does not exceed 1 mg/l, 16 h
after the end of exposure, the time-weighted average exposure is likely
to have been below 50 ppm. Exposure to such level for 6 years on the average
does not seem to exert any adverse effect on the central nervous system,
the liver and the kidney.

TITLE: Limited capacity of humans to metabolize tetrachloroethylene.

AUTHORS: Ohtsuki T; Sato K; Koizumi A; Kumai M; Ikeda M

SOURCE: Int Arch Occup Environ Health 1983;51(4):381-90

CITATION IDS: PMID: 6862652 UI: 83236973

ABSTRACT: Personal monitoring of exposure to tetrachloroethylene (TETRA)
with carbon felt dosimeters and analyses of urine for total trichloro-
compounds (TTC) were carried out in two groups of workers (36 males and
25 females), one group (20 males and 19 females) in dry-cleaning workshops
and the other (16 males and 6 females) engaged in the removal of glue from
silk cloth. Comparison of the urinary TTC levels with TETRA in the environment
revealed that, while the metabolite levels increased essentially linear
to TETRA concentrations up to 100 ppm, leveling off was apparent in the
metabolite excretion when the exposure to TETRA was more intense (e.g.
more than 100 ppm), indicating that the capacity of humans to metabolize
TETRA is rather limited, as previously discussed. From the set of the data
thus obtained, screening levels of 30 and 61 mg TTC (as TCA)/l urine as
the lower 95% confidence limits for a group mean were calculated for the
biological monitoring, by means of urinalysis, of exposure to TETRA at
50 and 100 ppm (TWA), respectively. A tentative calculation with additional
exhaled-air analyses indicated that, at the end of an 8-h shift with exposure
to TETRA at 50 ppm (TWA), 38% of the TETRA absorbed through the lungs would
be exhaled unchanged and less than 2% would be metabolized to be excreted
into the urine, while the rest would remain in the body to be eliminated
later.

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